board/nano-33-ble: pins, blinking leds and serial

targets/nano-33-ble.json

@@ -0,0 +1,7 @@
+{
+	"inherits": ["nrf52840"],
+	"build-tags": ["nano_33_ble"],
+	"flash-command": "bossac_arduino2 -d -i -e -w -v -R --port={port} {bin}",
+	"flash-1200-bps-reset": "true",
+	"linkerscript": "targets/nano-33-ble.ld"
+}

targets/nano-33-ble.ld

@@ -0,0 +1,14 @@
+
+/*
+  See also 
+  https://github.com/arduino/ArduinoCore-mbed/blob/master/variants/ARDUINO_NANO33BLE/linker_script.ld
+*/
+MEMORY
+{
+    FLASH_TEXT (rw) : ORIGIN = 0x10000, LENGTH = 0xf0000
+    RAM (rwx)       : ORIGIN = 0x20000000, LENGTH = 0x40000
+}
+
+_stack_size = 4K;
+
+INCLUDE "targets/arm.ld"